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Topic: 1230 Watt Solar Install (Read 1407 times)

The price of residential solar panels is coming down as the popularity of home solar goes up. Residential panels are often 72 cell operating near 40VDC. The more common ones use 6" ingots to produce the panel, making them about 39" wide. A few use 5" ingots, giving a panel that is about 32" wide. I couldn't make the 39" panels work on my unit, so I bought 6 of the 32" ones. Whether I bought 4 or 6 made little difference in price, as the cost of the panels is somewhat minor compared to international shipping, brokerage fees, (I live in Canada) and the price of the solar controller. I could fit 6 panels comfortably on the roof of our 2010 Arctic Fox 30U travel trailer. I already had a battery bank of 6 GC-2 cart batteries, and a 2500 watt inverter.

As some kind folks here have pointed out, shading of the panels can be an issue. Even a little shade from vents or air conditioners pretty much removes the panel, and anything connected in series with it, from the array. The panels I chose have 3 bypass diodes, which, IIUC, means the panel is divided into 3 areas. Shading will remove only the portion of the panel that is shaded from the array. As I chose 'high voltage' panels, I did not need to put them in series to provide the optimum input voltage to the Outback FM80 MPPT solar controller, which likes about 40V input to do its job. If one panel is shaded, only it is removed from the array, and then only if the whole thing is shaded.

I chose this arrangement because of what happened to us last year. We were under cloud cover most of the winter in Southern Arizona and SoCal. I wanted enough array to provide usable charge even on a cloudy day. We'll see if my theory works out.

Again, the kind folks here have told me that wiring on the roof in a typical solar installation needs to be UV resistant, or the insulation breaks down in time. It occurred to me that outside electrical conduit is UV resistant, and then I can use any wire I want. It also allows me to create a waterproof environment for the wiring, and a good mechanical attachment to the roof. That is what I am working with.

It was also suggested that I wire all the panels into a junction box on the roof before going down into the trailer, as this will allow some flexibility in the future should panels be added, removed, or whatever. Why not?

Another trick is to use the hole already in the roof for the fridge vent, and pass the wiring down there. For me, this looked like a good idea, as the wiring can go to the bottom of the fridge cavity, THEN into one of the lower cupboards in our coach, and on to the controller which will likely get installed beside the shore power coverter in the same cavity.

So here is my installation thus far using 6 x 205 watt Mexican panels. I will add to this thread as installation continues.

Next step was to put brackets on the solar panels so that I could attach them to the roof. So called 'z' bracket kits here are horribly expensive, and I can't imagine how anyone could remove a panel for replacement other than to remove the screws holding it to the roof. With potential leakage in my mind, I decided to attach brackets to the SIDES of the panels. Originally I had considered stainless steel machine screws, but found that the panels actually have a box section rather than a true channel in the frame. They look like this:

------|--| | | | |------|--|

Putting machine screws into that would just squash the box section. I could have used stainless screws, but they are terribly expensive. I finally decided to use aluminum pop rivets, buying short ones so that they just grip the outer wall only. If I need to remove a panel, I can leave the brackets in the roof, and just drill out the heads of the rivets.

I had 36 brackets 3" wide cut from 2" x 1" aluminum. Price was less than half of the 'z' brackets I could get here. I chose 6 to give additional support to the middle of the panel. Again, some here expressed misgivings about a residential panel in a mobile environment, so I chose to give them a bit more support.

The size of the brackets allowed me to mount the panels just far enough off the roof to allow the 1/2" conduit to fit comfortably under the panels.

Next step was the removal of the factory 140 watt panel. Northwood was kind enough to include a weather resistant cap over the connector. Just snap it on, and done! Though I will cover it with dicor before putting a new panel over that spot.

Then came a 'dry run' of the installation before I actually attach anything and put holes in the roof to do so. I used the cardboard packing that came with the panels (cut the same size as the panel) as a template to mark approximately where I would finally install the panels, and marked those spots with china marker. That allowed me to place the "T" boxes on the roof where they will be out of the way, and then measure and cut the conduit between them.

Once I was satisfied with the 'dry' assembly of the measured and cut pieces, I glued them all together, but I have still left them just sitting on the roof for the time being. I also bought a 1" spade type wood drill and bored a hole in the side of the fridge vent, and then screwed the conduit adapter into that. One should put a locking ring on the adapter on the inside of the fridge vent, but for that I would have to either cut through the mesh on the top of the vent to get at it, or remove the whole vent, something I was loathe to do. A little dicor will do nicely.

Next trick is to pull the wiring. I used #12 solid house wiring because it is cheap and the loss is well within limits. The far leg will have 4 panels wired into it, and the close leg (to the fridge vent) will have only two. All 12 wires will come together on the two bus bars in the octogon box, and then 2 #8 wires will take the power from the array down the 18 or so feet to the solar controller. The conduit is 1/2" everywhere except where it goes between the 3/4" Tee and the octogon box, and then down into the fridge cavity. That is because an electrician friend told me that 8 #12 wires would likely not fit in 1/2" conduit.

He also told me how to pull the wires properly using a fish tape and special lubricant made for this kind of thing. I have enlisted the help of my son in law to pull the 8 wires through from the T to the octogon box in one pull. Apparently one strips back about 6" of insulation on all the wires, twists the bare wires tightly together in a braid, leaving one longer than the rest. That is attached to the fish tape, and is used to pull all 8 wires through at one time. He will pull, and I will grease the wires with lubricant to ease the job. We'll see how THAT goes on Thursday.

Where in the trailer did you put the 500 pounds of battery? Is there a possibility that you are going to be significantly over the trailer GVWR when you have full fresh water tank and partly or mostly full gray & black tanks, in addition to your food, clothes and everything else you carry?

I bought a length of #8 - 7 strand copper to run between the octagon box and the FM80 Outback Solar Controller in the trailer. I measured, then added 10%, then rounded up to the nearest meter. It was BARELY enough. Lesson learned -- buy more than your reasonable calculations suggest. Would have been terrible to pull it all out again for the sake of a few inches.

Sadly, I had to either pull the fridge vent cover, or cut through the screen so as to be able to pass that stiff wire down the vent cavity. I started trying to remove the vent cover, but on a 7 year old trailer, it was just too much work, and the odds of breaking the cover were high. I chose to slit the screen off of half the vent. I haven't figured out yet how to reattach it, but likely some good rtv grade silicone will work.

From there I easily passed the wire down to the bottom of the fridge cavity, and stapled it in place. Now, how to get it into the coach? I began looking inside as to where the other wires in the cavity entered the unit, which turned out to be just above the furnace. Simple matter to drill one more hole, and pass it through there. I will seal it later with silicone sealer.

Instructions for the FM80 say that there should be a solar array cutoff switch, so I put one in. As Kevin Means suggested, a battery cutoff switch from an automotive parts store will do well ($19). Considering where I had to run the cable through the cabinets, the best place for the switch (and the most accessible) was inside the fridge cavity itself, so that is where I put the bright yellow and red switch. Had to move the AC outlet for the fridge a bit, but no issue.

Then it became time to pull the rest of the #12 wires through the 1/2” conduit. Two or 4 wires are easy. You can push them through as they are stiff enough. 8 wires came together in the “T” box, and had to be pulled through the 3/4” conduit to the octagon box. With the help of my son in law and some special wire lubricant, pulling them through went quite well! He also did the heavy lifting in putting the panels onto my work area – the top of my carport, which is the same height as our trailer.

I had purchased a couple of bus bars from a local electrical supplier that were a bit long for the octagon box. A hacksaw fixed that.

But then, looking at the 12 wires coming into the octagon box, and the 2 #8 wires going out, I began to wonder if it was all going to fit. It did – quite nicely – even leaving some slack for 'future considerations”. I only needed to put one wire in each hole, and some long-nosed pliers did a good job of inserting them.

Next came getting wire out of the conduit so they could be attached to the panels. I used some flexible cable cable clamps used specifically for that job – except they are usually attached to a threaded hole. I just used a bench grinder to take the threads off, then glued them into the end of the conduit. Results were not wonderful, but it seems to work. I will cover them with dicor in the final install 'just in case'.

I soldered the MC4 connectors to the ends of the #12, making sure to put the screw cap on first, THEN solder the pin. As it turned out, that was not necessary. The cap fits over the pin as it has a compressible weather fitting that squashes down when you tighten it – the same as the cable clamps.

Next step was to place all the panels in their approximate positions, and connect them. I did this one by one, then checked for voltage across the buss bars in the octagon box. If the panel checked out, I then disconnected it, and went on to the next one. That way I was sure that EACH panel worked. Would be sad to install 6 panels and have one or more of them fail to work because of a wiring flaw. How would one know?

Final picture is of the roof with the 6 panels in their approximate places. I need to dicor some holes in the roof from the previous panel, and seal the ends of the conduit before connecting all 6 panels, then screwing them in place. I bought a roll of butyl tape, and I intend to put some under each bracket before I screw it to the roof, then dicor the screws and the base of the mounting brackets.

Another thing I learned – don't try to 'slide' the panels on a hot rubber roof – not even an inch or so. One can easily tear the membrane.

I hope to attach all the panels on Sunday, and then to post some 'performance reports' after that.

Yeah, a lot of solar, but not a lot of watts, really. I looked up some solar performance specs at latitude, and as I originally guesstimated, it will be an amazing day if I get half of the rated wattage on the business end of the solar controller. If I manage 50 amps (600 watts) on a sunny day in Arizona at high noon in the winter, it will be something for the record books. With your tiltable 970 watts of panels, you will probably outdo my flat 1230 watts of panels.

However, the whole point of my project was not to set records. It was originally motivated by what was possible, and what was affordable. As you well know, the FM80 Outback controller is definitely NOT cheap (I should have bought the FM60). The controller alone cost me more than 2 panels, and the shipping cost me more than two more. So, the cost of panels themselves in a solar setup is relatively minor.

My idea was to more or less 'cover the roof' in panels whether they give full efficiency or not. On a cloudy day, I should still get usable power, with the overall goal of not having to run the generator anymore at all. We boondock most of the time, and I crave the quiet. Also, when looking at the old 'home brew' rigs in the LTVA's in the Quartzsite area, I don't see my system as being unreasonable. Anyway, if we are able to go south this winter, I guess we'll find out. I'll PM you the dates for KOFA should this take place.

I got the installation completed on Sunday. We have been in a 'heat wave' here in Calgary during most of the install, with temperatures around 30 to 33 degrees C (86 to 92 F). Maybe not hot for the desert folks, but not to be trifled with for us northerners. And I'm not young anymore. :-( However, by the time I was finally able to 'throw the switch' and connect all 6 panels to the controller, the weather had changed, and we had high thin overcast. However, even with that, I got 36 amps into a 70% charged battery bank at 11 AM DST (10 AM standard, or solar time). Today it rained, but I was not able to check it then. I will show more figures here when they become available. With correction for latitude, we get the same amount of solar energy here in Calgary in July as Yuma gets in March, so whatever I record now will be the high end of what I can expect when down south during the winter.

In any case, all I want is to SILENTLY keep my batteries up while we are in the desert for a few weeks. Our electrical demands are not high, but they seem to grow with time. :-) I should be able to leave the cell booster running 24/7 with this setup, not worry about watching some TV in the evenings, freely use the microwave for convenience items (popcorn, danish pastry), use the electric toaster (or the waffle iron for my dear wife), or leave the computer running longer than needed. No way I can run an air conditioner off this, but I have yet to need it down south in the winter anyway.

I do VERY MUCH appreciate your coaching on this (both in the forum and some PM's). Your experience was invaluable in getting this set up.

It was my pleasure Frank. I'm glad you're happy with how it turned out. Yeah, those FM-80s aren't cheap, but they're very programmable, very robust and (so far) very reliable. Keep me posted on how your system is working. Hopefully see you in KOFA.

Now, cloud cover is infinitely variable, so this observation is certainly not scientific. However, it is totally overcast (disk of sun not visible) and raining steadily in Calgary today. At 12:00 noon (11:00 AM solar) I am getting 17 to 25 amps into the battery bank. That is triple what I ever got in the direct sunlight with the factory installed 110 watt panel and PWM controller.

Now THAT is what I was looking for!

It is supposed to clear up over the next couple of days, so if it gets totally clear like it says it is supposed to on Thursday, I'll post again with the near noon results.

What do you have for a battery bank in your rig? We are looking for basically what you want. To be able to boondock and be as self sufficient as possible with solar power. We have a low income and would rather use it to enjoy nature than to give it to a corporate campground.

Logged

Taking the road less traveled usually means a few bumps along the way, but a lot more freedom and happiness.

When trying to determine what size solar array and battery-bank you'll need to live off-grid without a generator, you'll first need to know some things like, how much power you typically consume in a 24 hour period, and where in the country you'll typically be camping. Some people recommend one watt of solar for every Amp Hour (AH) of battery storage capacity. For example, if you had 200 AH of battery capacity, you'd need 200 watts of solar.

I haven't found that to be very realistic. We have an 840 AH battery-bank, and on a sunny winter Arizona/So Cal day, our 970 watt array was just barely enough solar to not have to run the generator at all - and that's when the panels were flat-mounted. Tilting them toward the sun made a huge difference in the panels' output, which also helps on cloudy days.

As noted in my original post, I have 6 GC-2's for a battery bank, for a nominal 600 amp hours. This is about the most I can possibly do given the weight limitations of our unit, and the space available for the batteries.

With about 1200 watts of solar, this is double the 'rule of thumb' recommendation that Kevin quotes for you. So, really, my system is solar heavy, and battery light. I don't have enough storage for the solar output that my panels are capable of generating. This means that I may end up fully charged by early afternoon, and 'waste' the solar energy available for the rest of the day. For my needs, I think this will be alright.

My panels are all flat mounted, and at least one of them may be subject to some shading during the day depending on how the trailer is parked. Therefore, I will be happy with even 50% efficiency, or 600 watts. That is 'bang-on' the 1 watt per amp hour recommendation.

I am not looking to disconnect from the grid and suck up every last erg of energy available. I just don't want to have to run my generator, ever again. Our energy needs are low, but I would like to be able to meet them on cloudy days as well as sunny ones. For this reason, I chose to go solar heavy. Not efficient, but hopefully will achieve what I am looking for. Time will tell.

I strongly suggest that you pay close attention to what Kevin offers to you. He is well experienced, and what I have posted here in my very first solar project.

It is my observation that with our four GC-2 batteries(~440 amp hours) and 600 watts of solar, that if you are not going to tilt your panels, you should have at least 1.5 times the amp hours of your batteries in watts of solar, and two times is not over kill.

As some kind folks here have pointed out, shading of the panels can be an issue. Even a little shade from vents or air conditioners pretty much removes the panel, and anything connected in series with it, from the array. The panels I chose have 3 bypass diodes, which, IIUC, means the panel is divided into 3 areas. Shading will remove only the portion of the panel that is shaded from the array. As I chose 'high voltage' panels, I did not need to put them in series to provide the optimum input voltage to the Outback FM80 MPPT solar controller, which likes about 40V input to do its job. If one panel is shaded, only it is removed from the array, and then only if the whole thing is shaded.

..........

So here is my installation thus far using 6 x 205 watt Mexican panels. I will add to this thread as installation continues.

First two pictures is the roof before I started doing anything.

OK, we get one small clue with "Mexican panels", don't suppose we could get a specific manufacturer/model? Being abler to compensate for partial shading would be huge in the RV world, I would think, but 3 pages of Googling doesn't show me anyone claiming such a setup in their panels....

Yeah, I spent hours before I came across these panels, and even then I only found them by accident. They apparently also come in 6 diode versions, but I could not locate any. I was told by the tech guy where I bought them that there is a tradeoff in the number of diodes used. He just said "If you build them for marginal performance, then you will get marginal performance." :-)

I have held off with specific information on my sources until I get a shipping problem resolved between the people I bought from and Fedex. I paid a hefty premium to have the panels delivered to my residential address, but then Fedex wanted an additional $123 just to use the power lift gate to put them on the ground. Had I known the price at the time, I would have refused. I expected another $20.

Now, how they expected me to have a fork lift at my home to put a 281 lb pallet shipment the remaining 3 feet onto the ground when the shipping instructions listed the weight, that it was on a pallet, and that I had requested and paid for a residential delivery, I fail to understand. Hopefully the otherwise EXCELLENT company that I bought the products from will be able to sort this out with Fedex so that I can publicly praise them. In the meantime, I am being somewhat evasive.

However, for your sake, I am attaching a couple of pictures that should give you what you need. Watch this space for an update on whether I can recommend the supplier without reservation or not. I really hope that I can, as they have been amazing up to this snag.

OK, Fedex would not relent on the additional shipping charges, so beware. I feel that the additional $123 charge (a very disproportionate 25% over the quoted price) to use the lift gate on a truck already equipped with a lift gate to go the last 3 feet to the ground was very unfair. They knew it was a pallet shipment of close to 300 lbs to a residential address. Expecting me to have a fork lift was unreasonable, and their additional charge to use a lift that was already there on the truck making the delivery is about as honorable as a 'balloon' payment at the end of a car loan. If you choose to ship, get a price quote for 'on the ground', and question the a** off them to be sure there are no other hidden charges. VERY disappointed with Fedex.

With that said, Ameresco Solar was a very honorable company to deal with. They gave me a competitive quote on all the components, and Rebecca Sanchez was very attentive to the shipment from beginning to end. She also steered me toward the panels I eventually bought, explaining that the ones I had originally shown interest in were overkill for my application, being designed for extremely rugged remote field use.

Ameresco Solar is a big company with offices all over the world, so I don't know for sure which branch I dealt with. However, they have offices in Arizona and San Diego among other places. Despite that, they paid close attention to my small order just the same as if I were buying for a solar farm. That kind of service is really nice.

Hope you're going to put a meter on one of those panels to see the output... I'm guessing the diodes may knock that back a bit

Not likely that I will ever test them individually. What I get is what I get. I'm not really that concerned about efficiency as I planned it so that I would have WAY more solar capacity than my needs warrant so that I won't ever have to run the generator again -- even on cloudy days. If I waste some efficiency, I'm only wasting sunlight, and that is still free. As I mentioned in my original post, the cost of panels is somewhat dwarfed by the cost of the controller and shipping. I don't think panel efficiency is a big issue, unless you are designing a marginal system and HAVE to get every last erg of energy per square inch to meet your needs.

Was just curious about what amperage you're really getting out of a panel... and would be interesting to know how much of THAT is actually getting to the charge controller. I found the panels by a process of elimination using the various "clues" in your earlier posts; i.e. 32", 205W, and was looking at the spec sheet here:

regarding their rated output. That diode job isn't anything to be proud of and I was just curious as to what effect, if any, it might have on the overall efficiency. I get that if you make a panel for mediocre performance, that's what you get, I'm more curious as to the company's accuracy in reporting their equipment's capabilities. Helps when deciding what is actually a "deal" as far as Amps/$ invested goes I would think.

I guess that will now have to wait until I can put them to the test. I hope to find out in Arizona this winter.

Summer has been entirely TOO busy, and though I WANT to get back to this project, I just can't seem to find a couple of free, sunny days. I need to do some programming of the controller as the absorb voltage causes gassing of my flooded cells. I think I need to set a current limit, but I suspect that this will be based on the average draw of the trailer with nothing but 'background' tasks running, and I haven't even determined that yet.

I also want to run a heavy load (like a heater and/or microwave) while the controller is in bulk mode to see how much the panels can put out 'pedal to the metal'. I already know that the controller can give the batteries more than they can take, so I need to up the ante on the load.

As to the soldering job, what is wrong with it? They are hot joints -- done by hand rather than machine. Isn't that what one would expect from Mexico where people (sad to say) are cheaper than machines?

As to reported output vs real output, the voltages are within a whisker of what they claim, and amperage is at least as much a function of cloud and lattitude as the quality of the panels. Methinks thou art chasing percentages too small to worry about.

OK, the preliminary figures are in. 50.7 amps on a relatively clear day with the sun just past solar noon, which is just about optimal for the way my trailer is parked at the moment.

I compromised by paralleling the solar controller to the converter, and thereby using the factory wiring to transmit the power to the battery bank from the converter. This is about a 20' run. The coach wiring is #6 wire where it connects to the converter, but appears to be lighter gauge where it connects to the batteries. I'm sure I could improve the performance if I rewired with #2 or heavier, but that is not in the cards at the moment. This was never about chasing maximum efficiency, but more about pragmatism.

With that said, however, I am QUITE pleased with just over 50 amps at this latitude (51 degrees) in August on a day where the air is still somewhat filled with thin smoke from the forest fires burning in the province to the west of us.

I consider the project a success at this point. Now I hope we can go south this year and park it in the desert for a few weeks and enjoy it all!

Don't you just love looking at the output of an MPPT controller that's converting volts to amps. 50 amps per hour is great Frank, and I'm quite sure it's significantly more than your consumption. Just remember that the US/Canadian exchange rate is about 1.275 to 1 right now, so you're not going to get as much sunshine up there as you will down here.

Don't you just love looking at the output of an MPPT controller that's converting volts to amps. (http://www.rvforum.net/SMF_forum/Smileys/default/smiley.gif)

Yes, very much. I had to Instagram that shot to my family.

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50 amps per hour is great Frank, and I'm quite sure it's significantly more than your consumption.

Yes, far more than I will ordinarily use. However, it is the 17 to 25 amps in full cloud and rain that I was really reaching for. Max amps is of lesser concern to me, other than the pure excitement of seeing that on the screen.

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Just remember that the US/Canadian exchange rate is about 1.275 to 1 right now, so you're not going to get as much sunshine up there as you will down here. (http://www.rvforum.net/SMF_forum/Smileys/default/cool.gif)

It is good to see the exchange rate coming evening out a bit. Taking a 30% hit last year was hard on the savings, which was only partly offset by the lower diesel prices in the States (massive taxes on fuel in Canada). Hopefully the exchange will improve yet more before we hope to head south.

Got our first chance to actually put the new solar to work this past week and see how it does.

Conclusion: Regardless of the solar capacity you have, if you park in the shade, it will never be enough.

We went into the mountains and pine forests just S and W of Calgary to a limited service (pit toilets, no power, water or sewer) Provincial campground that we have enjoyed for some 12 years or more. Where we have parked in the past was more a function of view than sunshine, though over the years we have noted one spot that is 'hotter' than the rest, and have mostly avoided that one. This time we were not able to get our preferred spot, so took one that is among some tall pines. Lovely site, but shady. The solar was not able to keep the 6 GC2 batteries charged with liberal use of the microwave, computer, and my color laser printer/scanner that I used to digitize some old photos. I had decided to make this a REAL test of the system.

We just didn't realize how little sun gets into this site. About 80% shade most of the day, with about 2 hours of 10% shade between 1 and 3 pm. The solar charger never got out of bulk mode, never being able to muster enough power from the array to reach the 14.4v needed to go into the absorb stage.

After 4 days, it was getting to the point that I began to feel a need to run the generator, but just did NOT WANT to throw in the towel that easily. So we moved to the 'hot' spot, and all problems were resolved.

This site has about 60% shade most of the day, with pretty much full sun between noon and 4 pm. The solar charger got the battery charge voltage up to 14.4 volts near 2 PM, and then kept it there for the default 1 hour before switching into 'float'. I increased the time limit on the absorb stage to 1.5 hours on the last 2 days, but should probably increase it well beyond that based on what I have learned from "Battery University". Batteries came back up to almost full charge the 3 days we were in that spot, though high cloud reduced performance on the last day.

It also appears that that the more aggressive charging algorithms in this Outback FM80 solar controller have somewhat rejuvenated my 3 year old battery bank that has otherwise only seen input from the 60 amp Progressive Dynamics shore power converter, and the anemic 110 watt factory solar with pwm controller.

So, we had enough power 'to burn' when parked in the sun, but just enough to get by when we weren't. Not a surprise, of course, but this was after all a test run. I am looking very much forward to seeing what happens if/when we get down south into the sunny Arizona desert this winter.

We boondocked for a week last year under a canopy of pine trees in the Oregon mountains. There wasn't a single minute that any of our panels were in direct sunlight. My brother had two portable panels for his TT and even those couldn't be kept in full sunlight. We had to run our generator for about an hour each morning, which wasn't too bad considering our coach's consumption. It was certainly better than having to run it four hours a day like we used to before installing the solar.

We have now been in Arizona for about a month, and just over a week S of Quartzsite in a great boondocking area. I am pleased with the performance of our system.

Our travel trailer is typical of middle-of-the-road units in that it uses propane appliances. We don't watch a lot of TV, tending to use tablets to stream Netflix. Therefore, our electric needs are not heavy and it appears that we have more than enough solar to do pretty much what we want with electrical power. I've not needed the generator since we left Canada a month ago (though we did have shore power a couple of nights on the way down).

On sunny days, the batteries will only take 30 to 40 amps from the controller before they go into absorb around 11 AM. However even that much draw seldom happens as we have only gotten to a 50% discharge over 24 hours when we were much further North, and had to run the furnace a lot. Therefore, I have found that the FM80 is way overkill for our needs. The FM60 would have been more than necessary as well. However, the Outback controller is VERY programmable, and should we one day go for Lithium batteries, I am all set.

I brought a full-size Brother MFC-9330CDW multifunction laser printer/scanner with us this time as I want to digitize a lot of our old photo albums. It works fine off the 2500 watt Sunforce inverter. My wife brought her waffle iron, and we took our 600 watt electric toaster. We have the typical RV microwave of about 1000 watts, and just for a lark, we also took along a hot air popcorn popper that draws as much as the microwave. I even brought my Makita professional rotary buffer / polisher to spruce up the exterior of the trailer, and I've been running that off the inverter as well.

This past week we have not spared ourselves any electrical conveniences. Nothing we throw at the system seems to tax it in any way. In full sunlight in January the Outback FM80 solar controller puts the 6 Interstate (Costco) GC-2's into float by about 1 PM. Even on somewhat cloudy days, we get a full charge long before the sun begins to wane.

My overall design philosophy of 'cover the roof with residential panels' seems to have worked well. The FM80 works well with the 40 v panels, and I have zero need of tilting those panels as we have SO MUCH capacity already with them flat. Even the occasional shade on the panel beside the a/c doesn't affect things much -- again because of the admittedly over-designed solar array. The use of these 32" wide panels still allows me room to walk around on the roof as well.

So, residential panels are 'cheap', and no one ever seems to say that they have too much solar. I'm glad that I put a lot of panels up there, as the extra cost and work was not that much more.

OK, the preliminary figures are in. 50.7 amps on a relatively clear day with the sun just past solar noon, which is just about optimal for the way my trailer is parked at the moment.

I compromised by paralleling the solar controller to the converter, and thereby using the factory wiring to transmit the power to the battery bank from the converter. This is about a 20' run. The coach wiring is #6 wire where it connects to the converter, but appears to be lighter gauge where it connects to the batteries. I'm sure I could improve the performance if I rewired with #2 or heavier, but that is not in the cards at the moment. This was never about chasing maximum efficiency, but more about pragmatism.

With that said, however, I am QUITE pleased with just over 50 amps at this latitude (51 degrees) in August on a day where the air is still somewhat filled with thin smoke from the forest fires burning in the province to the west of us.

I consider the project a success at this point. Now I hope we can go south this year and park it in the desert for a few weeks and enjoy it all!

Frank.

Before I left Lake Havasu I went to Lowes and got the end of a roll of #2 cable, (about 50 feet). I also got battery lugs and I have a crimping tool.

I was going to suprise you at KOFA with free new #2 cable for your battery to Invertor cable that you mentioned in the above post.

Yep... Bill is a generous guy, which reminds me... Thanks again for the filter Bill. I really appreciate it! And if you ever accidentally buy the wrong batteries, like maybe 800 AHs of lithium batteries, please offer them to me first.

I'm glad your solar setup is working so well Frank. Sounds like it's all dialed in... but a popcorn popper?? Boy, this boondocking lifestyle's gettin' tough! Thanks for coming by the other day. It was nice to finally meet you. We ended up with 11 RVs and a tent at our boondocking site, and everyone seemed to have a great time. We sure did. We had originally planned to stay 4 or 5 nights, but ended up staying an entire week. What a great group!

During the entire week, I only ran our generator for about 15 to 20 minutes one evening, so Cyndi could nuke some things in the microwave for our group potluck dinner. Other than that, it was all solar. Not bad considering we have such a power-hungry coach. Several of us in the group had solar. It's a pretty popular option in that part of the country.

And my thanks to you. It was a pleasure to meet you and your wife as well. Sorry that we are so shy, but with the pressure of life today, even when retired, the wife and I seek QUIET more than anything else. In fact, I complained to one of my buddies back in Calgary about how much I hate sitting beside the fridge outside under the awning. I hate the 'roar' of the propane burner. :-) THAT is the kind of quiet we crave, something that we find in abundance here. It would be nice to get to know you better in a smaller group.

And my thanks to Bill as well. I'll have to look him up in the phone book and send him a big 'Thank You' card when we get home.

Safe journey home. We're off to Agua Caliente in Anza Borrego once we finish a shopping trip to Yuma on Monday (if the somewhat overzealous ranger doesn't chase us out on Friday).😄